This invention relates to the field of automatic analytical instruments, and, more particularly, the invention is concerned with instruments for automatic clinical chemistry systems using sample carousels and sample handling systems.
Different clinical analyzers for automatic analyzers are known. One particular kind uses a plurality of individual analysis modules having open sample cups. An automated sample probe withdraws a sample volume from samples in the sample carried on a carousel. Selected volumes of the sample are distributed to analysis modules in accordance with tests selected by the instrument operator.
A different kind of analyzer uses a flow cell through which diluent flows together with fluid samples for determination of electrolytes in the fluid sample. Usually, four electrolytes, namely, sodium, potassium, chloride and CO.sub.2 are determined in the flow cell. In such analyzers, a sample pick-up probe extends vertically through a shear valve to aspirate the fluid sample from a sample cup aligned with the probe. The tip of the probe is withdrawn into a shear valve and the lower portion of the valve closes. Diluent from a diluent source flows into the valve, is mixed with the sample from the probe and flows to a flow analysis module.
Each of these different kinds of analyzers have their unique advantages in the analysis of fluid samples. For instance, the first analyzer enables the parallel analysis of samples using incompatible reagents that could not be used in a flow cell analysis module. On the other hand, a flow cell analyzer provides simplified fluid handling and minimizing reagent consumption.
The present invention is particularly directed to the flow cell analyzer and systems for improving the movement and operation of various components, particularly, the sample carousel or wheel, and the sample-handling system.